1. Field of the Invention
The present invention concerns an external combustion engine, such as for example a Stirling engine, which exploits a cycle of isothermal expansion and compression of a thermodynamic fluid, for example air, nitrogen, helium or others, to determine the alternate and cyclical movement of a displacer and a cylinder, so as to entail the rotation of a determinate drive shaft. In particular, the present invention concerns an external combustion engine with a nominal power able to be modulated.
2. Description of Related Art
External combustion engines are known, for example Stirling engines, which exploit a temperature difference caused in a thermodynamic fluid and actuate the cyclical and alternate movement of a displacer and a cylinder.
The displacer and the cylinder are kinematically connected to each other and to a drive shaft, which transmits to the user device the power delivered.
In this type of known engines, it is therefore sufficient to cause a temperature difference in the thermodynamic fluid to start the functioning of the engine.
Although they are silent to run, have low environmental impact, low maintenance and other characteristics, these engines do not allow variations and modulations of their nominal power, and substantially function always at the same capacity.
This limitation has led to such engines being used almost exclusively in applications where a continuous and constant delivery of energy is necessary.
Therefore, an application of this type of known engines for traction or propulsion, in which continuous variations in power are required, has progressively been abandoned.